Insulated flag-type terminal



June 1956 L. M. CURTISS INSULATED FLAG-TYPE TERMINAL Filed March 27,1955 w I I I I I,

INVENTOR. LAWRENCE M. CURTISS ls\\\\\\\\\\\\\\\\\ IIIIIIIIII QTTORNEYWSULATED FLAG-TYPE TERIWINAL Lawrence M. Cnrtiss, Mountainside, N. 5.,assignor to The Thomas & Betts Co., Elizabeth, N. 3., a corporw tion ofNew Jersey Application March 27, 1953, Serial No. 344,926

Claims. (Cl. 339-223) The invention relates in general to a shieldedcable terminal of the flag type, and specifically relates to such aterminal which includes a metallic barrel intended to receive aninsulated cable, and which barrel is contained in a shield and isdesigned to be deformed conventionally by squeeze pressure appliedthrough the shield into a crimped engagement with the bare ends of thecable conductors within the barrel.

The primary object of the invention is to provide such a terminal as anarticle of manufacture with an insulating shield already in place andwhich will protect the barrel and at the same time leave fully exposedfor attachment to other conductive articles the outstanding integraltang which forms an integral part of flag-type connectors.

Broadly, this objective is attained by premolding a shield of insulatingelastic plastic material, one end of which constitutes a cylinder withinwhich a barrel element of the metallic flag terminal may be received andby providing the outlining wall of the cylinder with a slot-like openingthrough which the tang can extend when its barrel is in its prelocatedplace in the cylinder end of the shield.

Still another object of the invention is to provide a form of insulatingshield which with its metal barrel in position will tend to avoid, or atleast to minimize, the infiltration of dust into its interior and thusminimize the presence of foreign matter in the finally formed terminal.

The invention in the forms illustrated contemplates forming the shieldwith a tubular extension at one end to form a reinforcing skirt forembracing and protecting the insulating jacket of the cable or cables inthe parts thereof adjacent the bared conductor ends.

Various other objects and advantages of the invention will be in partobvious from an inspection of the accompanying drawings and in part willbe more fully set forth in the following particular description of threeforms of flag-type cable terminal each embodying the invention, and theinvention also consists in certain new and novel features ofconstruction and combination of parts hereinafter set forth and claimed.

In the drawings:

Fig. 1 is a top plan view looking down on a shielded cable terminal ofthe flag-type constituting a preferred embodiment of the inventionparticularly designed to receive an end of a cable and with parts brokenout at one end to show internal construction;

Figs. 2 and 3 are sectional views taken, respectively, on the lines 22and 3-3 of Fig. 1, in each case looking in the direction indicated bythe arrows;

Fig. 4 is a view in axial section of the shielded terminal of thepreceding figures taken on the line 44 of Fig. 2 and secured to the endof a cable;

Figs. 5-7 are views of a first modified form of the invention designedto receive the end of a cable and in which Fig. 5 is a longitudinalaxial sectional view taken on the line 5-5 of Fig. 6 and with an end ofa cable crimped in place; Fig. 6 is a transverse sectional view taken onthe line 6-6 of Fig. 5 after the cable has been 2,749,529 Patented June5, 1956 ice inserted therein and the barrel crimped onto the bare cableends; and Fig. 7 is a right end view of the terminal of Fig. 5 beforethe cable is inserted therein;

Fig. 8 is a view in side elevation of a second modified form of shieldaspect of the invention, showing a flap form of closure for the openingprior to the insertion therein of the tanged barrel; and

Fig. 9 is a transverse sectional view taken on the line $-9 of Fig. 8,and with the flap momentarily held in its open position.

In the drawings and referring first to the disclosure in Figs. l3, thereis shown an article of manufacture comprisirn solely two parts, ametallic connector it) of a flag-type and a preformed insulating shield11 of an insulating plastic material for enclosing and thus protectingthe barrel part of the connector.

The connector is of somewhat conventional form and comprises a strip ofconductive metal, in this case, sheet copper, with one end rolled backupon the strip to form an open-end barrel 12, leaving the balance of thestrip flat to form a tang or tongue 13 extending tangentially away fromthe barrel. As usual, the tang is provided with an aperture 14 and isotherwise designed to provide an electric contact with some otherconductive object, as is usual with flag-type connectors.

The shield i1 is formed of a plastic, non-conductive and heat-resistantmaterial and having at least some degree of plastic memory. In the caseillustrated the shield is formed of a synthetic condensation polymericamide manufactured by the E. I. du Pont de Nemours & Co. under thedesignation of nylon and one form of which is disclosed in the patent toGordon, No. 2,348,536, granted May 9, 1949.

The shield is premolded to shape, is of one-piece, of tubular form, andone end forms a cylinder 15 and its other end forms a skirt 16, with thebores of the cylinder and skirt coaxially related. The end of thecylinder opposite the skirt is closed by an end wall 17 which acts toprovide an internal brace t0 the cylinder at its closed end.

The portion of the bore of the cylinder in which the barrel l2 fits isof a slightly larger diameter than the bore of the skirt to form aninternal stop shoulder 18 operative to defeat axial shifting of thebarrel in a direction towards the skirt. The end wall 17 acts as a stopto defeat movement of the barrel in the opposite axial direction asshown in Fig. 4. In this way the barrel 12 is fitted into an annulargroove formed in the bore of the shield between the shoulder 18 and theend wall 17.

The diameter of the groove so formed in the cylinder bore is dimensionedto receive the barrel with a snug fit and the diameter of the skirt boreis dimensioned to provide a snug fit with the insulating jacket B of thecable A hereinafter described.

it is a particular feature of this disclosure that the wall of thecylinder is provided with an elongated slot-like opening 19 extendingparallel to its longitudinal axis and dimensioned to permit the tang 13to extend therethrough with a close fit therein to close the opening.

in the devices illustrated, where the shield is made of a plasticmaterial as indicated, the internal diameter of the cylinder is moldedslightly less than the external diameter of the barrel which it isintended to embrace so that, as the shield tends to shrink back to itsmolded configuration, it tends to bind the cylinder frictionally on thebarrel.

In mounting the barrel in place in the shield it is an approved practiceto stretch the plastic cylinder radially at the opening 19, suflicientlyto permit the barrel to be passed sidewise therethrough and locatedwithin the cylinder between the stop shoulder 18 and the end wall 1'7,

leaving the tang outside of the shield and then releasing theclistending stretching forces to permit the shield by reason of itsplastic memory to return automatically to its initial moldedconfiguration in a squeeze binding engagement with the barrel. In thisway the cylinder 15' at all i res restores itself thereby engaging andclamping itself snugly to the barrel.

In the finished article the tang extends in a plane substantiallytangent to one side of the cylinder 15, as best shown in Fig. 2.

The shielded flag-type terminal as thus formed constitues a completearticle of manufacture and is so placed on the market, ready to have thestripped-back end of a cable inserted therein.

A right or left-handed terminal can be fabricated selectively from theparts herein disclosed, depending on the tr e connector is inserted intothe barrel of the pie ,ic shield.

The connector so formed is utilized to form a flag terminal to an.electric cable, for instance, as illustrated in Fig. 4. in this casethere is shown a cable A of the aircraft type with an insulating jacketB which is stripped back f om one end to expose a bundle C of strandcon- The cable is inserted with its bare conductors in advance,successively through the bore of the skirt and then through thecylindrical bore of the barrel until stopped by the conductorscontacting the end wall 17. The barrel is then deformed transverselywith an indentation E extending from the upper side laterally onto thebundle of conductors by a squeeze pressure applied to the barrel throughthe insulatin cylinder along the line indicated by the arrow in Fig. 4and as more fully described in the co- 'rding application of John NelsonFrey, Serial No.

,;62, filed June 26, 195i.

By means of the form of plastic preformed insulator disclosed there isprovided maximum insulation around both the terminal and the adjacentportion of the cable insulation with the least possible use ofinsulating material and disposed in close relation to the barrel toprevent the nfiltration of foreign matter into the cable terminal. The 51g fit of the skirt end of the shield over the cable insulation jacket Bgrips and supports the same and prevents the end of the cable insulationfrom fraying. The shirt is of annular form, externally tapering to anose at its free end and. of greatest cross section of material at theshoulder The portion forming the shoulder 18 is of maximum cross sectionof material and this tends to reinforce the slotted tubular portion. Inthis case the skirt hugs the jacket B frictionaily.

it is suggested that in those cases where it is desired for any reasonto extend the bundle of connectors through and beyond the terminal ahole he provided in the center of the end Wall 3.7 of sufficientdiameter to permit the conductors to pass therethrough, leaving themarginal portion of the closure 17 as an. annular flange to form anabutment against which the adjacent end of the barrel 12 may engage.

Referring specifically to the first modified form of the inventionillustrated in Figs. 5-7, the end portion 28 of the plastic shield,which receives the cable, is enlarged over the portion which receivesthe barrel 12. The bore of the end portion 20 is twice reduced to forman outer thin-walled sleeve 21 of relatively small cross section of aland an inner thick-walled sleeve 22 of greater cross section ofmaterial. The end of the inner sleeve at its cable-receiving end isbeveled inwardly to form a It is understood that the Figs. 5-7 form ofthe invention may be utilized to receive a diiferent form of cable thanis shown in Fig. 5 The bore 26 of the outer sleeve 25. is dimensioned toreceive the insulating jacket of a cable with a sliding fit. In suchcase the beveled end can act as a stop to limit the intrusion of theinsulation jacket and with it the intrusion of the cable end into thefitting.

in this form of the shield, the opening 25 for receiving the barrel 12is of greater arc length than is the corremat rial length of the barrell2 exposed as shown at 27 for receiving an indentation H for crimpingthe barrel onto the bare ends of conductors received in its bore, asshown in 6. Under certain circumstances, the free end of the barrel 12may be welded to the tang 13 along the iointure 28, thus defeating anytendency of the tang a sting from the barrel, incident to the operationof running the indent H. In this way the metal barrel may be crimpedonto the bare ends of the conductors by pressure applied directly to thebarrel along a squeeze line approximately along the section line S-5 ofFig. 6, and thus the plastic shield need not become involved in any wayin the crimping operation.

Rer'e rig to the second modification of the shield elemerit of thedisclosure, the end portion which is to receive the barrel is slit alongspaced-apart parallel lines and transversely of the molded shield fromthe opening 15.9 for about eighty-five degrees arc length to form narrowslots 33$ and 39. The slots are spaced apart a distance to permit theinsertion into the shield of the barrel 12 as previously described. Theportion of the shield between. the slots forms a flap-like closure 31connected along the hinge line 32 to the balance of the shield. Inoperation, the closure 31 is elevated as shown in Fig. 9 to enlarge theopening 1') and through this enlarged opening the barrel may be freelyinserted sidewise as previously described for the insertion of barrel 12through the smaller size opening 19. When released the closure returnselastically to its closed position, leaving the opening it? as shown inFig. 8 and no wider than is necessary accommodate the extensiontherethrough of the tang shown in Pig. 2. In this case, the barrel maybe held in the shield, even ignoring its frictional engagement therewithand ignoring the closure 31, by reason of the fact that the shieldencloses the barrel for more than a half circle, that is, for an arcdistance of about 237 degrees, as viewed in Fig. 9.

Moreover, the skirt id be omitted but its presence does tend toreinforce the cylindrical portion provided with the slotted opening 15The disclosure particularly features economy in manufacturing cost. Theshield can be molded as a one-piece article by conventional moldingprocesses, and the metal connector likewise can be formed by standardpractices. The barrel element of the connector can be passed through theside opening in the shield by unskilled labor and with the assurancethat the parts will fit exactly as intended and with the bar cable endinserted the unit so preferomed may be subjected to conventionalcrimping practices to secure the flag-type terminal to the cable.

I claim:

1. A terminal fitting including a preformed molded shield of insulatingmaterial having an axially extending bore and forming at one end atubular portion fashioned to receive the metal barrel of a connector,said tubular portion provided along one side thereof with an axiallyextending opening through which the metal barrel may be insertedsidewise, the bore at its other end being twice reduced to form an innersleeve spaced from both ends of the shield, and an outer sleeve defininga cable inlet for the shield, and the inner sleeve at its end nearestthe outer sleeve being beveled to form a funnel-like entrance openingfrom the portion of the bore encircled by the outer sleeve into theportion of the bore encircled by the inner sleeve.

2. A terminal including an inner cylindrical metal barrel having a borefashioned to receive wire conductors, a shield of insulating materialhaving a bore in which the metal barrel is at least partially contained,said shield provided along one side with an opening through which themetal barrel is passed sideways, a part of the barrel being exposedthrough the opening to provide an area adapted to be deformed bycrimping apparatus into a binding engagement with conductors in the boreof the barrel without involving the shield in the crimping operation.

3. A terminal for an electrical conductor comprising the combinationwith a cylindrical metal barrel having a bore for receiving an end ofsaid conductor and adapted to be crimped into binding engagement withsaid conductor end; of an insulating container for said barrelcomprising, a sleeve of resilient insulating material having a lengthsubstantially greater than said barrel and an inner diametersubstantially equal to the diameter of said barrel and having at oneside a window-like opening longitudinally dimensioned to permit passageof the ends of said barrel between the ends of said opening andtransversely dimensioned to permit forced passage of the side walls ofsaid barrel between the sides of said opening by momentary deflection ofits longitudinal edges; said opening thereby permitting forced sidewiseentry of said barrel to contained position therein and thereupon leavingexposed an area of said barrel for indentation by crimping apparatusinto binding engagement with said conductor end.

4. A terminal for an electrical conductor comprising the combinationwith a cylindrical metal barrel having a bore for receiving an end ofsaid conductor and adapted to be crimped into binding engagement withsaid conductor end; of an insulating container for said barrelcomprising a cup-like sleeve of resilient insulating material having alength substantially greater than said barrel and an inner diametersubstantially equal to the di ameter of said barrel, said sleeve havingat one side a window-like opening extending longitudinally from itsclosed end to a dimension to permit passage of the ends of said barrelbetween the ends of said opening and transversely dimensioned to permitforced passage of the side walls of said barrel between the sides ofsaid opening by momentary deflection of its longitudinal edges, saidopening thereby permitting forced sidewise entry of said barrel tocontained position therein and thereupon leaving exposed an area of saidbarrel for indentation by crimping apparatus into binding engagementwith said conductor end.

5. An insulated flag-type terminal connector for an insulated electricalconductor including an inner metallic barrel portion having an openingtherethrough for the intrusion therein of a bare end portion of saidconductor, comprising an insulating shield in the form of a hollowcylinder of resilient plastic material closed at one end thereof andhaving a length substantially greater than said barrel portion and aninternal diameter substantially equal to the diameter of said barrelportion, said cylinder having an elongated opening therein extendingfrom its closed end through an arc of the periphery of said cylinder on-a chord measured by said are whereby the longitudinal and transversedimension of said opening is such as to permit said barrel portion to beforceably inserted through said opening into said cylinder with theopposite end faces of said barrel portion in abutment respectively withthe partially closed end of said cylinder and the opposite end of saidopening intermediate the ends of said cylinder, and with an insulatedportion of said conductor, adjacent said bare end portion, extendinginto the annular open end of said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS422,058 Mclntire Feb. 25, 1890 1,315,135 Rocco Sept. 2, 1919 1,946,713Rowley Feb. 13, 1934 1,967,014 Taverner July 17, 1934 2,146,612 AldenFeb. 7, 1939 2,289,512 McKenney July 14, 1942 2,623,085 Gier Dec. 23,1952 2,701,273 Badeau Feb. 1, 1955

